The present invention relates to a bright medium-range telephoto lens suitable for use in taking portraits, and more particularly to a photographic lens system having an F number up to 1:1.4 with spherical aberration and astigmatism corrected sufficiently for coverage ranging from objects at an infinite distance to those at a closest distance.
Medium-range telephoto lenses having an F number of 1:1.4 and a focal length of 85 mm are widely used in taking portraits. However, it is difficult for prior medium-range telephoto lenses to correct aberrations over a full image height within the depth at the brightness of 1.4. In particular, where the sagittal curvature of field is too small for assuring performance at an outermost peripheral edge of the field, the lens system tends to suffer from shortcomings in that astigmatism is increased in medium angles of view and images cannot be well focused, resulting in images having blurred profiles in portraits.